Pharmacognosy Research

ORIGINAL ARTICLE
Year
: 2017  |  Volume : 9  |  Issue : 3  |  Page : 221--229

Uncaria tomentosa (Willd. ex Schult.) DC (Rubiaceae) sensitizes THP-1 cells to radiation-induced cell death


Lisa Allen1, Alison Buckner1, Carly A Buckner1, Pablo Cano3, Robert M Lafrenie2 
1 Program in Biomolecular Science, Laurentian University, Sudbury, ON P3E 2C6; Health Sciences North, Sudbury, ON P3E 5J1, Canada
2 Program in Biomolecular Science, Laurentian University, Sudbury, ON P3E 2C6; Health Sciences North, Sudbury, ON P3E 5J1; Division of Medical Science, Northern Ontario School of Medicine, Sudbury, ON P3E 2C6; Health Sciences North Research Institute, Sudbury, ON, P3E 5J1, Canada

Correspondence Address:
Robert M Lafrenie
Health Sciences North Research Institute, 41 Ramsey Lake Road, Sudbury, ON P3E 5J1
Canada

Background: Uncaria tomentosa (Willd. ex Schult.) DC (Rubiaceae), known as Cat's Claw or Uña de gato, is a traditionally used medicinal plant native to Peru. Some studies have shown that U. tomentosa can act as an antiapoptotic agent and enhance DNA repair in chemotherapy-treated cells although others have shown that U. tomentosa enhanced apoptosis. Objective: To determine if treatment with U. tomentosa can significantly enhance cell death in THP-1 cells exposed to ionizing radiation. Materials and Methods: THP-1 monocyte-like cells were treated with ethanolic extracts of U. tomentosa in the presence or absence of bacterial lipopolysaccharide and then exposed to ionizing radiation. Cell proliferation was assessed by MTT and clonogenic assays and the effects on cell cycle measured by flow cytometry and immunoblotting. Changes in cell signaling were determined by immunoblotting and cytokine ELISA and activation of apoptosis measured by caspase activation and DNA fragmentation analysis. Results: Treatment of THP-1 cells with U. tomentosa had a small effect on cell proliferation. However, when the U. tomentosa-pretreated cells were also subjected to 5–9 Gy ionizing radiation, they showed a significant decrease in cell proliferation and increased cellular apoptosis as measured by DNA fragmentation and caspase activation. Treatment with U. tomentosa also decreased the expression of Cyclin E and Cyclin B, key regulators of normal cell cycle progression, and decreased the phosphorylation of various stress-activated, cell survival proteins including p38, ERK, and SAP/JNK kinase. Conclusions: These results suggest that U. tomentosa could be useful in enhancing cell death following anticancer therapies including ionizing radiation.


How to cite this article:
Allen L, Buckner A, Buckner CA, Cano P, Lafrenie RM. Uncaria tomentosa (Willd. ex Schult.) DC (Rubiaceae) sensitizes THP-1 cells to radiation-induced cell death.Phcog Res 2017;9:221-229


How to cite this URL:
Allen L, Buckner A, Buckner CA, Cano P, Lafrenie RM. Uncaria tomentosa (Willd. ex Schult.) DC (Rubiaceae) sensitizes THP-1 cells to radiation-induced cell death. Phcog Res [serial online] 2017 [cited 2017 Nov 20 ];9:221-229
Available from: http://www.phcogres.com/article.asp?issn=0974-8490;year=2017;volume=9;issue=3;spage=221;epage=229;aulast=Allen;type=0